Turning joint for pipes

ABSTRACT

Two pipe ends are interconnected through ball bearings having their two races connected respectively to two telescoped retaining rings. A sealing ring is disposed and retained between these rings in the center plane of the bearings. The sealing ring has smaller diameter than the bearings.

United States Patent Josef Friihlich; Mar. 14, 1972 [54] TURNING JOINTFOR PIPES [56] References Cited Inventors: Josef F fiihlich,Dusseldorf-Kath, Germany; UNITED STATES PATENTS l JawbLeguytDmdrecmNetherands 1,737,465 11/1929 Lindsey ..285/275 x [73]Assignee: Mannesmann Aktiengesellschaft, Dussel- 2,549,951 4/1951Warren.... .....285/276 X 2,689,753 9/1954 Wechsler ..285/272 3 468 5649/1969 Friilich n..285/276 X Fl 7 A [22] Sept l9 0 3,514,127 5/1970Brooker .285/276 x [2l] Appl.No.: 75,912

Primary Examiner-Reinaldo P. Machado Assistant Examiner-Wayne L. Shedd[30] Apphcam Pmmy Dam Attorney-Smyth, Roston & Pavitt and Ralf H.Siegemund Sept. 30, 1969 Germany ..P I9 50 324.3

[57] ABSTRACT [52] U.S.Cl ..285/276,,285/28l 51 1111.01 ..Fl6l 27/08 TWOP P ends are lmemnnected through ball beafmgs [58] Field 01 Search..285/276, 280, 281,278, 275, ing their two races connected respectivelytelescoped 285/272, retaining rings. A sealing ring is disposed andretained between these rings in the center plane of the bearings. Thesealing ring has smaller diameter than the bearings.

2 Claims, 1 Drawing Figure v I I 5 7 I7 [Tfi 1111 i ,4 j 4 4 z 2 7V V" 7r l8 .1 10/5816 re TURNING JOINT FOR PIPES The present invention relatesto a turning joint for pressurized pipes and including bearings withrolling elements and two races that are connected individually to thetwo pipes. Joints of that type require additionally a sealing ring whichis usually disposed between the two race defining elements of thebearings. Turning or rotatable joints for connection of pipes are neededin articulated pipelines as they are employed for loading and unloadingof tankers or tanker trucks. Particularly a loading boom for running apipe to a moored vessel needs pipe connections that permit relativeturning of the interconnected piping.

Such a turning joint is subjected to considerable forces there is theinternal pressure, there are forces that pull on the pipes in oppositedirection, and particularly, bending forces occur which tend to tiltbearing parts Any displacement of the bearing parts relative to eachother by operation of the several forces is limited essentially bybearing play, i.e., by clearance and tolerances of the bearing elements.Still, tilting of the pipes changes the gap to be sealed by the sealingring. As long as the ring has sufficient elasticity or is spring biased,the change in the dimensions of the gap will be of little consequence.However, in cases the pipes serve as conduit for a medium whose chemicaland/or physical characteristics require employment of particularmaterial for the sealing ring that has little elasticity.

The problem solved by the present invention is to provide a turningjoint for pipes in which the gap to be sealed will undergo only littlechanges in dimension, particularly in case bending forces act on thejoint, so that sealing material of low elasticity can be employed,because other requirements are more important. For regular use of thepipes, the effective gap should be adjustable particularly to offset anylong term changes. Situations requiring low elasticity type sealingrings rise where the medium running through the pipeline is highlycorrosive or liquefied natural gas having temperature of about l80Centigrade. Regular use is, for example, the conveying of crude oil.

In accordance with the present invention, it is suggested to locate thesealing ring in the plane of the circle as defined by the centers of therolling elements of the bearings, whereby the sealing ring is disposedwithin that circle, having smaller diameter than the latter accordingly.Thus, in case of tilting of the tubes so interconnected and for an angledetermined by the bearing tolerances, the sealing gap changes dimensionsto a lesser degree. This, in turn, limits the elasticity requirementsfor the sealing ring in that gap.

in accordance with the preferred embodiment for practicing theinvention, inner and outer race, defining bearing rings, arerespectively connected to two telescoped retaining rings defining aradial gap. The sealing ring is disposed in that gap. The two retainingrings each have an axial flange; the flange on the inner retaining ringextends radially out, while the flange on the outer ring extendsradially inwardly. These two flanges define a particular axial length ofthat radial gap. The sealing ring is disposed, for example, so as toabut the inwardly directed flange, assuming that the flange has axialdistance from the plane defined by the bearing circle smaller than thewidth of the sealing ring so that the latter ring is in fact traversedby that plane. Axial spacer means are interposed between the otheroutwardly directed flange and the sealing ring to determine the preciseaxial length of the gap for and occupied by the sealing ring. The spacermeans are preferably comprised of a ring and of one or several spacerelements.

A particular advantage of the construction in accordance with theinvention is to be seen in that the parts that undergo maximum wear,i.e., the sealing ring and the spacer means, are readily replaced.

While the specification concludes with claims particularly pointing outand distinctly claiming the subject matter which is regarded as theinvention, it is believed that the invention, the objects and featuresof the invention and further objects, features and advantages thereofwill be better understood from the following description taken inconnection with the accompanying drawings in which:

The FIGURE illustrates partially a section view, partially a sideelevation of a pipe joint improved in accordance with the preferredembodiment of the invention.

Proceeding now to the detailed description of the drawing, there isshown a turning joint for interconnecting tubes or pipes 1 and 2. Thetwo pipes have common axis 12. The connection is essentially provided bymeans of ball bearings having a ring 6 defining an inner race. Race 6 isbolted to a flange member 4 which, in turn, is for example, welded tothe end of pipe 2. An outer ring 5 defining the outer race of the ballbearings is bolted to a flange 3 that, in turn, is welded to the end ofpipe 1. Balls 7 are disposed between the two races defining rings 5 and6.

An inner retaining ring 8 having a flange 14 is bolted to and receivedby inner race 6. Flange 14 extends radially outwardly from ring orsleeve 8. An outer retaining ring 9 has a flange 13 by means of whichring 9 is bolted to outer race 5. Flange 13 extends radially inwardlyfrom ring or sleeve 9. Retaining ring or sleeve 9 extends, radially,between ring or sleeve 8 and bearing ring 6, but clearing the latter.The two retaining rings, 8 and 9, define a particular radial gap whoseaxial dimensions are determined by the distance between the two flangesl3 and 14; a sealing ring 10 is interposed between rings 8 and 9, withinthat gap.

The sealing ring 10 has diameter that is significantly smaller than thediameter of the ball bearings as defined, for example, by the circle onwhich the centers of the balls 7 are located. That circle defines acenter plane 11 of the bearings; plane 11 extends transverse to pipeaxis 12 which is also the turning axis of the joint. The sealing ring 10is traversed by that plane 11. I

The assembly includes a plurality of O-rings 18 disposed in suitablegrooves for sealing 3, 5 and 18 as one group and parts 4 and 14 as theother group of fixedly interconnected elements.

Having shown the actual position of sealing 10, the definition of thatposition is arrived at as follows. In particular, sealing ring 10 has aspecific axial position between rings or sleeves 8 and 9 which requiresthe two flanges 13 and 14 to extend on opposite sides of plane 11. Thataxial position is determined, on one hand, by abutment to flange 13 ofring 9. On the other hand, spacer means 15-16 are comprised on anaxially displaceable compression ring 15 having bevelled surface thatbear against bevelled wedges 16. Thus, there is a plurality of thesewedges l6, distributed uniformly around the axis 12 and adjacent to ring15. However, each wedge 16 is displaceable transverse to the directionof displacement of ring 15; that is radially outwardly. Each wedge piecemay be so displaced through manipulation of an associated adjustingscrew 17.

As it can be seen, the axial dimension of the sealing gap occupied byring 10 is determined by the axial distance between flange 13 and ring15. That distance becomes adjustable through radial displacement ofwedges l6.

This way, in turn, compression of sealing ring 10 can be adjusted fromthe exterior.

Ball bearings are shown in the example above, but roller bearings mayalso be employed.

The invention is not limited to the embodiments described above but allchanges and modifications thereof not constituting departures from thespirit and scope of the invention are intended to be included.

We claim:

1. Connection between two pipes that permits relative turning of thepipes on their axes, the connection to include rolling friction-typebearings having a first ring connected to one of the pipes and definingan inner race and a second ring connected to the other one of the pipes,defining an outer race for rolling elements in between, comprising:

a first retaining ring connected to the first bearing ring;

a second retaining ring connected to the second bearing ring andcircumscribing the first retaining ring, there being a radial gapbetween the first and second retaining rings, the center plane of thebearings as defined by the location of the rolling elements, traversingthat gap;

a radially outwardly directed flange on the first retaining ring;

a radially inwardly directed flange on the second retaining axial spacermeans in the gap and positioning the sealing ring, the two flangesaxially displaced to and on opposite g in axial direction that th Centerplane runs sides of said center plane; through the sealing ring.

a sealing ring in said gap between the first and second connecfion as inclaim 1, sRacer means including retaining rings and having axialdimensions smaller than means for adjustment of the effecuve 8X13]length the axial distance of the two flanges; and

1. Connection between two pipes that permits relative turning of thepipes on their axes, the connection to include rolling friction-typebearings having a first ring connected to one of the pipes and definingan inner race and a second ring connected to the other one of the pipes,defining an outer race for rolling elements in between, comprising: afirst retaining ring connected to the first bearing ring; a secondretaining ring connected to the second bearing ring and circumscribingthe first retaining ring, there being a radial gap between the first andsecond retaining rings, the center plane of the bearings as defined bythe location of the rolling elements, traversing that gap; a radiallyoutwardly directed flange on the first retaining ring; a radiallyinwardly directed flange on the second retaining ring, the two flangesaxially displaced to and on opposite sides of said center plane; asealing ring in said gap between the first and second retaining ringsand having axial dimensions smaller than the axial distance of the twoflanges; and axial spacer means in the gap and positioning the sealingring in axial direction so that the center plane runs through thesealing ring.
 2. Connection as in claim 1, the spacer means includingmeans for adjustment of the effective axial length.